There was a time when Yahoo was one of the most successful internet companies in the world.

But in recent years, it has made more headlines for struggling to find growth for its core business, and missing on big opportunities.

Photo-sharing site Flickr is perhaps the best poster child for Yahoo’s failures.

Flickr, founded in 2004 by Stewart Butterfield, was once considered the best online photo-sharing service in the world. But after getting acquired by Yahoo in 2005, it was “murdered and screwed out of relevance,” according to Gizmodo.

Instagram and Facebook proved that there is a large, lucrative market for slick photo sharing. Yahoo should have used Flickr to create a rival to those companies.

“It was really frustrating,” Butterfield said in a recent interview with Business Insider, when asked about his experience with Yahoo.

Further elaborating, Butterfield perfectly sums up what might have caused all the problems at Yahoo:

I think I learned a lot, and overall it was a good experience. But it was so hard to get the resources that we needed. I think we missed out on so many opportunities where Flickr could have been a lot bigger and more successful than it was as part of Yahoo — because of Yahoo’s internal ‘screwed up-ness.’

When asked about Flickr specifically, Butterfield says he has “mixed feelings,” although he likes a lot of the changes that Yahoo has made over the years.

Even with new managment, Butterfield has his doubts. “I think it doesn’t have, to my mind, a clear focus. It’s a little hard to tell what it is, what they’re trying to do, what the focus of Yahoo is,” he told us.

As Butterfield points out, what Yahoo needs might just be better internal communications and a focused strategy.